This invention relates to the technical field of fiber-reactive azo dyes.
Fiber-reactive azo dye mixtures and their use for dyeing hydroxyl- and carboxamido-containing materials in greenish to reddish brilliant blue hues are known for example from Anthraquinone and Dioxazine dyes. However, they have certain performance defects, for example an insufficient color buildup at high dye concentrations, which ultimately compromises the economics of the dyeing operation. Anthraquinone dyes, such as Reactive Blue 19, do not exhibit good build-up properties and are limited to specific dyeing applications, i.e. exhaust dyeing. In contrast, Dioxazine dyes exhibit good build-up properties, but are highly dependent on specific dyeing conditions, i.e. salt and alkali amounts in exhaustion dyeing.
Consequently, there continues to be a demand for novel reactive dyes or reactive dye mixtures having improved properties, such as steep color buildup coupled with good fastnesses without special dyeing conditions. They shall moreover also provide good dyeing yields and have high reactivity and they shall more particularly provide dyeings having high degrees of fixation.